text: """
  You are given an m x n 2D image matrix (List of Lists)
  where each integer represents a pixel. Flip it in-place
  along its vertical axis.
  
  Example:
  Input image :
  1 0
  1 0
  
  Modified to :
  0 1
  0 1
  """
  
  
  def flip_vertical_axis(matrix):
      for i in matrix: i.reverse()
  